Impairment of two types of circulating endothelial progenitor cells in patients with glucocorticoid-induced avascular osteonecrosis of the femoral head.

Department of Orthopedics, Union Hospital, Tongji Medical College, Science and Technology of Huazhong University, Wuhan 430022, China.
Joint, bone, spine: revue du rhumatisme (Impact Factor: 2.25). 04/2012; DOI: 10.1016/j.jbspin.2012.02.015
Source: PubMed

ABSTRACT OBJECTIVES: This study examined whether abnormalities of early EPCs and endothelial colony forming cells (ECFCs) are present and compared their functions in glucocorticoid (GC)-induced avascular osteonecrosis of the femoral head (ANFH). METHODS: Early EPCs and endothelial colony forming cells (ECFCs) were obtained from 33 patients with glucocorticoid-induced ANFH and 33 age- and sex-matched control subjects. Cells were isolated, in vitro cultured and studied by Flow Cytometry and Immunofluorescence. Colony-forming unit counts were observed from 33 patients and 33 healthy controls. Growth kinetics, migratory capacity to multiple chemo-attractants, in vitro tube formation capacity and cytokine (vascular endothelial growth factor and stromal cell-derived factor-1) levels in supernatants of two types of EPCs were assayed in ANFH patients and matched controls (n=4). RESULTS: Mean numbers of colonies formed by both types of EPCs were decreased in ANFH patients (Early EPCs: 2.42±1.46 versus 4.52±2.00, p<0.05; ECFCs: 0.62±0.55 versus 1.12±0.82, p<0.05,). Early EPCs from ANFH patients showed impaired migratory capacity (63.8±11.7 versus 152.3±12.4, p<0.001) and VEGF secretion (50.8±7.2pg/ml versus 62.8±10.1pg/ml, p<0.05). ECFCs from ANFH patients showed decreased tube formation capacity (7.1±2.7 versus 23.8±4.3, p<0.001) and proliferation. DISCUSSION: Early EPCs and ECFCs were impaired in number and function in GC-induced ANFH, and their distinct reduced capacity profiles might reflect different roles they played in endothelial dysfunction of GC-induced ANFH.

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